Hygiene habit training aid

ABSTRACT

There is provided a soap that contains an indicator that produces an observable change after a period of time to show that sufficient cleaning has been done or to indicate the thoroughness of the cleaning. The soap is preferably made from two components that produce a color and/or viscosity changes after about 30 seconds of use. This use indicating change is useful for, for example, teaching children to wash their hands for a sufficient period of time.

This is a divisional application of commonly assigned U.S. patentapplication Ser. No. 10/107,383, filed Mar. 27, 2002, and claims thebenefit of filing priority therefrom.

BACKGROUND OF THE INVENTION

The present invention concerns soap for hand, body and surface washing.

Soap and water are effective cleaners and, depending on ingredients, canbe effective in fighting bacteria and other causes of illness. In manycases, effective cleaning and disease control occur only after certainperiods of time or at elevated temperatures. While it may be arelatively simple matter for adults to judge the appropriate time forwashing, this is not always the case with children. Children, whether inbrushing teeth or washing hands, for example, tend to spend less time onthe task than desired by parents and other caregivers. This can resultin ineffective cleaning.

It is, therefore, quite important for children to learn the correct wayof completing a key hygiene task such as brushing teeth or washinghands. In order for these habits to form at an early age, parents orguardians typically rely on constant reminders and close monitoring. Ittakes a lot of time and attention from the parent or the guardian intheir attempts to build and reinforce these hygiene habits. Further,children tend to follow the instructions only as long as they feel theyare being monitored. Most often, children grow up learning these habitsonly as a result of pressure from their parents or guardians, and do notmaintain these habits once the pressure of close monitoring is absent.

An important aspect of building these hygiene habits is to involve thechildren in completing the task in a way that focuses their attention onthe hygiene activity in a non-threatening and natural manner. One way ofaccomplishing this would be to introduce an element of fun and play sothat children enjoy completing the task while building these habits.Another way would be give them a sense of accomplishment by providing afeedback signal they can easily understand and associate with correctlycompleting the task. If there is an element of fun and play in additionto a clear feedback indication, children are likely to complete thehygiene task without any need for close supervision and monitoring bytheir parents and guardians.

Various approaches have been used to remedy this problem. In the case oftooth brushing, flavored toothpastes have been developed to encouragechildren to brush longer, because they like the taste. This approach isnot available for soap, however. A clock or timer can also be used buthas drawbacks as well.

There remains a need, therefore, for a soap product that may be used bya consumer and which will give an indication of when sufficient use hasoccurred. It is an object of this invention to provide such a useindicating soap.

SUMMARY OF THE INVENTION

In response to the discussed difficulties and problems encountered inthe prior art, a new cleaning aid has been developed wherein the aidcontains an indicator that provides a change detectible by a user aftera period of time after dispensing has passed. The cleaning aid may be,for example, a soap, and the change may be in color, in viscosity, insmell, temperature or even in sound. The observable change may occur infrom a finite time to at most 5 minutes or more particularly about 45seconds, or still more particularly between 15 and 35 seconds.

If the cleaning aid is a soap, the soap is preferably made from a firstcomponent including liquid soap and a dye, and a second componentincluding ascorbic acid and iron chloride. The components are mixedtogether to produce the soap. The soap may change color from green toblue.

The soap may alternatively have liquid soap and polyvinyl alcohol, andoptionally, a second component including borax and citric acid.Alternatively, the soap may be liquid soap and a second component, whichis an ion sensitive polymeric material. In yet another alternative, thefirst component may be liquid soap and a polyoxyalkylene blockco-polymer, and the second component may include polyacrylic acid. Inyet another alternative, the soap may have a first component includingliquid soap and a cationic cellulosic quartenary ammonium derivative,and a second component including polyacrylic acid. The components aremixed together to produce the soap.

The soap changes viscosity from a gel to a liquid. The soap changesviscosity in from a finite time to at most 45 seconds after thecomponents are mixed together. More particularly, the soap changesviscosity between 15 and 35 seconds after the components are mixedtogether.

The soap may alternatively have a first component including liquid soap,a dye and polyvinyl alcohol, and a second component including borax,citric acid, ascorbic acid and iron chloride. The components are mixedtogether to produce the soap. The soap changes viscosity from a gel to aliquid and simultaneously changes color from green to blue. The soapchanges viscosity and color in from a finite time to at most 45 secondsafter the components are mixed together. More particularly, the soapchanges viscosity and color between 15 and 35 seconds after thecomponents are mixed together.

This invention also encompasses a hygiene teaching aid and a method ofdeveloping a hygiene habit. The hygiene teaching aid has an indicatorthat provides a change detectible to a user after a period of time afterdispensing has passed. The method of developing a hygiene habit includesthe steps of dispensing soap and water into a user's hands, rubbing thehands together until a change detectible to the user is detected, andwashing the hands with water, where the soap contains and indicator thatprovides the change after a period of time after dispensing the soapinto the hands has passed.

DETAILED DESCRIPTION OF THE INVENTION

It has long been a concern to parents that their children wash for asufficiently long period of time to remove dirt and/or kill any illnesscausing organisms on their skin. Since children tend to hurry throughthis task, however, parents are often frustrated in their success inthis area. The inventors believe that a soap that indicates when apresumably sufficient time of washing has passed will aid parents andother caregivers in the task of teaching children proper washingtechniques. The inventors believe that children will find their soap tobe fun and playful and will enjoy using it, thus building andreinforcing proper hygiene habits.

Another aspect of cleaning, more problematic with surface cleaning thanin handwashing, is to avoid missing areas entirely. In cleaning akitchen or bathroom counter, for example, areas may be missed, and theremay be no indication that the area has not been washed. An indicatorthat told the user that all areas he desired to be washed were indeedwashed would be important in many areas, such as the cleaning of medicaland dental tools, infant bottles and pacifiers, utensils and many more.In this respect, the soap of this invention may be thought of as acleaning “thoroughness” indicator.

The amount of time needed to clean the skin or a surface has beenresearched extensively. The Center for Disease Control (CDC), a divisionof the US Department of Health and Human Service, Public Health Service,has developed guidelines for such cleaning. The CDC Guideline forHandwashing and Hospital Environmental Control, 1985 notes at page 7that “the ideal duration of handwashing is not known, but washing timesof 15 seconds or less have been reported as effective in removing mosttransient contaminants from the skin”. The CDC Guidelines at page 9recommend “for routine handwashing, a vigorous rubbing together of allsurfaces of lathered hands for at least 10 seconds, followed by thoroughrinsing under a stream of water”. The Association for Professionals inInfection Control and Epidemiology (APIC) Guideline for Hand Washing andHand Antisepsis in Health-Care Settings (1995) also recommends a washtime of 10-15 seconds at table 1 for routine hand washing. Antimicrobialsoap or detergent or alcohol-based handrub is recommended to remove ordestroy transient microorganisms, while soap or detergent arerecommended to remove soil and transient microorganisms.

The APIC Guideline also notes (page 7) that traditional surgical handscrubbing is performed in the United States and Europe for 5 minutes.The instant invention may be formulated in such a way as to indicatewhen larger periods of time have passed by the appropriate choice ofingredients.

In its broadest embodiment, the invention includes soap and an indicatorthat provides an observable change after a period of time. It preferablycontains at least one dye or pre-dye and a modifying agent that causes achange to occur. These components may be kept separate until washing isbegun, or may be mixed in a manner such that the change does not occuruntil washing. Thus the components may be kept in a two part dispenseror may be kept together with one component inactive by some means, suchas by microencapsulation, until sufficient physical stimulus results intheir effective mixing. The components may also be kept separate bybeing a simple non-miscible mixture of two phases.

The soap of this invention may be made to indicate that a presumablysufficient time has passed by any mechanism that may be observed by auser; color, smell, sound, temperature, and viscosity change and acombination thereof. These indicators may be activated through changesin pH, oxidation and reduction, metal complexing and gelation. Theseindicators may also be used to ensure that all areas one desires to havecleaned, whether on the hands, another body pail, or another surface,have indeed been cleaned.

Changes in color may be from colorless to colored, colored to colorless,or from one color to another. The viscosity change may be from liquid togel, liquid to paste, liquid to solid, and any permutation thereof. Asound may be generated or terminated at the appropriate time or a smellmay be generated, for example, for users unable to see color change.

The following embodiments illustrate the invention in varying scope.

An indicating soap was made starting with standard colorless,over-the-counter liquid soap, Kimberly-Clark Professional antibacterialClear Skin Cleanser (PCSC C2001-1824). A small amount of food grade dye,in this case 0.2 weight percent of FD&C (food, drug & cosmetic) greendye number 3 from BF Goodrich of Cincinnati, Ohio, was added to theliquid soap. Mixed separately were antibacterial soap and a decolorizingagent. The decolorizing agent was 1 weight percent ascorbic acid fromAldrich Chemical Company of Milwaukee, Wis. and 1 weight percent ironchloride also from Aldrich Chem. Co. When the two components are mixedin approximately equal proportions in the hand, for example, the colorwill initially be green. After about 30 seconds the color will graduallychange to blue. The speed of the color change is controlled by theconcentration of the decolorizing agent. The residual blue color isuseful in indicating how thoroughly the hands have been rinsed afteruse.

The viscosity changes of polymer solutions can be induced by manyfactors. One of them with viscosity increasing can be achieved bychemically or physically increasing the apparent molecular weight ofpolymers. The chemical methods include crosslinking reactions such aspoly(vinyl alcohol) solution mixed with borax, while the physicalmethods include forming inter-polymer complexes such ashydrogen-bonding, hydrophobic, and polyelectrolyte complexes. On theother hand, solutions of some special chemicals are dilatant or rheopexyfluids. Their viscosity changes with shear rate or time, and hence canalso be incorporated into liquid soaps to induce viscosity changes.

In a viscosity changing embodiment of the invention, the same colorlessliquid soap (PCSC C2001-1824) was used. FD&C green dye number 3 in anamount of 0.2 weight percent and 5 weight percent of polyvinyl alcoholfrom Aldrich Chemical, having an average molecular weight of 85,000 to146,000 and 87 to 89 percent hydrolyzed, was added to the soap to make afirst component. In this case, a mixture of 0.2 weight percent sodiumtetraborate decahydrate (Aldrich Chem.) and 2 weight percent citric acidin liquid soap was the second component. When the two components weremixed, a gel was formed in the hand. After some time, dependent in thiscase upon the concentration of the citric acid, the gel is broken downand the soap has a water-like consistency.

In another viscosity changing embodiment of the invention, about sameamount of an ion sensitive water-soluble polymer and liquid soap (PCSCC2001-1824) are applied from a two-chamber dispenser onto the hands. Thesystem viscosity dramatically increased and became very sticky in thehand washing process. The mixture is also easy to rinse off the handwith water. The ion sensitive polymeric materials are described in U.S.Pat. No. 6,194,517 to Pomplun et al., commonly assigned, which issuedFeb. 27, 2001 and in allowed U.S. patent application Ser. No.09/223,999, filed Dec. 31, 1998. The patent teaches water solublepolymers comprising from about 25 to about 90 weight percent of anunsaturated carboxylic acid/unsaturated carboxylic acid esterco-polymer; from about 10 to about 75 weight percent of a divalent ioninhibitor and from about 0 to about 10 weight percent of a plasticizer.The polymers are soluble in an aqueous environment having a divalent ionconcentration less than about 50 ppm and a monovalent ion concentrationof less than about 0.5 weight percent. The polymers are insoluble in anaqueous solution having a concentration of divalent ions greater thanabout 50 ppm.

Poly(acrylic acid) (from Aldrich, MW 45,000) was incorporated intoliquid soap (PCSC C2001-1824) with concentration of 10 weight percent.The mixture can be easily applied onto the hands similar to the originalliquid soap, but is very sticky in the hand washing process, andgenerates sticky fibers between the hands whenever the hands areseparated. The mixture is easy to rinse off the hands with water.

PLURONIC® F127 NF block copolymer and liquid soap (PCSC C2001-1824)solution was prepared with PLURONIC® F127 NF concentration of 15 weightpercent. This solution and a 10 weight percent poly(acrylic acid) (fromAldrich, MW 45,000) were applied onto hands from a two-chamberdispenser. The mixture has an obvious viscosity increase and becomesvery sticky in the hand washing process, yet is easy to rinse off thehands with water. Using 5 weight percent poly(vinyl alcohol) (fromAldrich, 99 percent hydrolyzed, MW 85,000-146,000) instead of 15 weightpercent PLURONIC® F127 NF has the similar effect. It should be notedthat the viscosity increases can also be induced bytemperature-responsive polymers alone, i.e. by the use of PLURONIC® typeblock co-polymers without the use of polyacrylic acid.

Block copolymers suitable for use in this system include polyols andthose of polyethylene glycol/poly(lactic-co-glyclic) acid. Commerciallyavailable block copolymers include PLURONIC® and TETRONIC® from BASF.Useful polyoxybutylene based block copolymers conform to the followinggeneric formula:HO(C₂H₄O)_(b)(C₄H₈O)_(a)(C₂H₄O)_(b)Hwherein a and b are integers such that the hydrophobe base representedby (C₄H₈O) has a molecular weight of at least about 500, preferably, atleast about 1000 and most preferably, at least about 3000, as determinedby hydroxyl number, the polyoxyethylene chain constituting at leastabout 60%, preferably, at least about 70% by weight of the copolymer andthe copolymer having a total average molecular weight of at least about5000, preferably, at least about 10,000, and most preferably, at leastabout 15,000.

The copolymer is characterized in that all the hydrophobic oxybutylenegroups are present in chains bonded to an organic radical at the formersite of a reactive hydrogen atom thereby constituting a polyoxybutylenebase copolymer. The hydrophilic oxyethylene groups are used to cap thepolyoxybutylene base polymer.

Polyoxyethylene-polyoxypropylene block copolymers which can be used toform aqueous gels can be represented by the following formula:HO(C₂H₄O)_(b)(C₃H₆O)_(a)(C₂H₄O)_(b)Hwherein a and b are integers such that the hydrophobe base representedby (C₃H₆O) has a molecular weight of at least about 900, preferably, atleast about 2500, most preferably, at least about 4000 average molecularweight, as determined by hydroxyl number; the polyoxyethylene chainconstituting at least about 60%, preferably, at least about 70% byweight of the copolymer and the copolymer having a total averagemolecular weight of at least about 5000, preferably, at least about10,000, and most preferably, at least about 15,000.

In addition to those polyoxyalkylene block copolymers referred to above,which are suitable in the formation of the compositions of theinvention, other polyoxyalkylene polymers which form gels at lowconcentrations in water are suitable. One such polymer is described inU.S. Pat. No. 4,810,503, incorporated herein by reference. Thesepolymers are prepared by capping conventional polyether polyols with analpha-olefin epoxide having an average of about 20 to about 45 carbonatoms, or mixtures thereof. Aqueous solutions of these polymers gel incombination with surfactants, which can be ionic or nonionic. Thecombination of the capped polyether polymers and the surfactants provideaqueous gels at low concentrations of the capped polymer and surfactant,which generally do not exceed 100% by weight total. Detailed methods ofpreparing these aqueous gels are disclosed in U.S. Pat. No. 4,810,503.

A CELQUAT® H-100 (a cationic cellulose quartenary ammonium derivativefrom National Starch & Chemicals) and liquid soap (PCSC C2001-1824)solution was prepared with CELQUAT® H-100 concentration of 1.5 weightpercent. This solution and a 10 weight percent poly(acrylic acid) (fromAldrich, MW 45,000) were applied onto the hands from a two-chamberdispenser. The mixture has an obvious viscosity increase and becomesvery sticky in the hand washing process, yet is easy to rinse off thehands with water.

In still another embodiment, the methods above were combined to producea soap that changed color and viscosity. The antibacterial liquid soap(PCSC C2001-1824) was again the base material. FD&C green dye number 3in an amount of 0.1 weight percent and 5 weight percent polyvinylalcohol were added to the soap to make one component. A second componentwas made with liquid soap, 0.2 weight percent FD&C yellow dye number 5(BF Goodrich), 1 weight percent sodium tetraborate decahydrate. A thirdcomponent was 2 weight percent citric acid dissolved in water. Uponmixing the components, a green gel is formed. After a time of about 30seconds, the soap's viscosity was reduced and its color slowly changedto blue.

In still another embodiments, the antibacterial liquid soap (PCSCC2001-1824) was again the base material and the following generalpreparation was used for all the experiments:

20 ml of the liquid soap was made containing 0.01 weight percent dye.This was physically mixed to ensure uniformity of color throughout theliquid.

20 ml of liquid soap was prepared containing 0.05 weight percent citricacid (Aldrich Chemical Co, Milwaukee, Wis.) and mixed to ensure it washomogeneously dissolved.

20 ml of liquid soap was prepared containing 0.05 weight percent sodiumcarbonate (Aldrich Chemical Co., Milwaukee, Wis.) and mixed to ensure itwas dissolved into the soap.

20 ml of liquid soap was prepared containing 0.01 weight percent copperchloride (Aldrich Chemical Co., Milwaukee, Wis.) was dissolved into theliquid soap.

Approximately 5 ml of the dye containing liquid soap was mixed with anequal volume of liquid soap containing the “activating agent” (e.g.citric acid etc) and the color change noted. COLOR CHANGE DYE FROM TOAGENT Red 28 Colorless Fluorescent red Citric acid Red 27 Pink BlueCopper ion Red 30 Yellow Red Sodium Carbonate FD&C Dyes (from BFGoodrich, Cincinnati, Ohio) Green 3 Green Blue Sodium carbonate Yellow 6Red Yellow Citric acid Food/Beverage Dyes (from Aldrich Chemical Co.,Milwaukee, WI) New Coccine Red Violet Sodium carbonate Litmas PinkPurple Sodium carbonate Carminic acid Pink Purple Sodium carbonate OtherDyes Alizarin complexone Yellow Purple Sodium carbonate Neutral Red RedYellow Sodium carbonate Thymol blue Yellow Blue Sodium carbonatePhenolphthalein Colorless Magenta Sodium carbonate Chlorophenol redYellow Red Sodium carbonate Bromothymol blue Yellow Green Sodiumcarbonate Nitrazine yellow Yellow Purple Sodium carbonate

Thus, a variety of color changing chemistries are available for theliquid soap formulations.

The soap of this invention may be dispensed by any convenient meansknown to be useful in dispensing two-component systems. Such dispensersare known in the art for dispensing shampoo and the like. These systemsmay use a squeeze bottle or a single plunger-type pump that displaces anapproximately equal volume of each component simultaneously. Adisposable form of this method of dispensing includes two components anda separator in a flexible pouch that may be torn or cut in a manner thatallows both components to be released. Examples of such dispensers maybe found in U.S. Pat. No. 5,645,822.

As will be appreciated by those skilled in the art, changes andvariations to the invention are considered to be within the ability ofthose skilled in the art. Examples of such changes are contained in thepatents identified above, each of which is incorporated herein byreference in its entirety to the extent it is consistent with thisspecification. Such changes and variations are intended by the inventorsto be within the scope of the invention.

1) A hygiene teaching aid comprising an indicator that chemicallyprovides a change detectible to a user after a period of time afterdispensing has passed. 2) A system for developing a hygiene habitcomprising the steps of dispensing soap and water into a user's hands,rubbing the hands together until a change detectible to said user isdetected, and washing the hands with water, wherein said soap containsan indicator that chemically provides said change after a period of timeafter dispensing said soap into the hands has passed. 3) The soap ofclaim 2 wherein said soap changes in color. 4) The soap of claim 2wherein said soap changes in viscosity. 5) The soap of claim 2 whereinsaid soap changes in smell. 6) The soap of claim 2 wherein said soapchanges in sound. 7) The soap of claim 2 wherein said soap changes intemperature. 8) The soap of claim 2 wherein said soap changes in from afinite time to at most 5 minutes. 9) The soap of claim 8 wherein saidsoap changes in between 25 and 35 seconds. 10) The soap of claim 2wherein said soap changes in from 10 to 45 seconds. 11) The soap ofclaim 2 wherein said soap changes in from a finite time to at most 2minutes.